... Anthropogenic habitats may serve as a refuge for aquatic species, including freshwater mussels (Bivalvia, Unionida). Evaluating the role of anthropogenic habitats is a fundamental, but still ignored, conservation issue given the pace that humans have been converting natural ecosystems. In this study, possible differences in abundance, size and condition index of the freshwater pearl mussel Margari ...

... The freshwater pearl mussel Margaritifera margaritifera is a highly threatened species in Europe. Several mechanisms may be responsible for the decline in distribution and abundance of European pearl mussel populations, but almost no quantitative data exists about the possible negative impacts of invasive alien species (IAS). In this study, we clearly demonstrate that the invasive signal crayfish ...

... Freshwater bivalves have suffered major global declines, being the introduction of invasive alien species (IAS) an important, but not well studied, mechanism of threat. This study assessed the predator-prey relationship between two non-native crayfish species (Procambarus clarkii and Pacifastacus leniusculus) and three native (Anodonta anatina, Potomida littoralis and Unio delphinus) and one non-n ...

... The IUCN Red List assessments are essentially based on population trends and range, namely Area of Occupancy (AOO) and Extent of Occupancy (EOO). Range estimations are based on fixed grids, but this is likely inappropriate for species living in river networks. Furthermore, AOO and EOO are measured using the whole hydrographic network, therefore disregarding temporary sections, which is particularl ...

... Droughts may be responsible for important ecological impacts in freshwater ecosystems, including the death of rare species. This study assessed the mortality of the endangered pearl mussel Margaritifera margaritifera (Linnaeus, 1758) in the Mente, Rabaçal and Tuela rivers (north west of the Iberian Peninsula) during the extreme summer drought of 2017. Mortality occurred as a result of the low rive ...

... The freshwater pearl mussel Margaritifera marocana (Pallary,) is an endemic species of Morocco being listed as critically endangered and it stands among the world's 100 most threatened species. An extensive survey was performed in the Sebou basin (total area of approximately 40,000 km²), covering 26 different sites. Margaritifera marocana was found only in four sites limited to a small tributary ( ...

... The natural variation of environmental factors in freshwater basins determines their biodiversity. Among them, calcium is a key physiological compound for freshwater invertebrates. It is required for shell formation, muscle contraction, it mediates gene expression and allows counteracting acidosis during stress periods, among other functions. Although the distribution of different freshwater speci ...

... Freshwater mussels of the family Unionidae are one of the most threatened groups worldwide and have suffered severe decline over recent decades. Although the freshwater duck mussel, Anodonta anatina (Linnaeus, 1758), is still widespread, this species has shown evidence of recent declines and is already protected in some European countries. Informed conservation efforts must take into account patte ...

... Margaritifera marocana is one of the rarest freshwater mussel species (listed as critically endangered), and is endemic to Morocco. Despite its constrained distribution and low abundance, to date there are no quantitative studies addressing the conservation status of this species. Surveys were conducted in 36 sites along the Oum Er Rbia river basin (Rivers Derna, Laabid and Oum Er Rbia) to assess ...

... Freshwater mussels of the order Unionida have been dramatically declining globally. Despite their ecological importance, conservation of these animals has been hindered by unresolved taxonomy and a lack of data on the distribution and status of populations, especially in southern Europe. Although the Italian Peninsula has been noted as a centre of endemism and one of the major refugia of the glaci ...

... Many doubts still exist about which freshwater mussel Unio species inhabit Northwest Africa. While some authors refer to the presence of Unio delphinus in the Atlantic North African basins of Morocco, a recent International Union for Conservation of Nature (IUCN) assessment performed on Moroccan Unio species, recognised the existence of a distinct species, Unio foucauldianus, with a critically end ...

... This contribution presents the first record of the freshwater jellyfish Craspedacusta sowerbii Lankester, 1880 in Greece. The species was found in a water transfer canal adjacent to Lake Marathon, 45 km northeast of Athens; this is the southernmost record of this invasive alien medusa in the Balkan Peninsula and Europe. A review of recently published records shows that this species has expanded it ...

... Based on new information, the current conservation status of the freshwater pearl mussel Margaritifera margaritifera (Linnaeus, 1758) in Portugal is revised. Between 2010 and 2013 surveys were conducted in eight different rivers to assess distribution, abundance, size-frequency and preferential habitat of this species. Rivers Neiva, Cávado and Terva presented very low abundances (in the Cávado no ...

... Two Unionida (freshwater mussel) families are present in the Northern Hemisphere; the Margaritiferidae, representing the most threatened of unionid families, and the Unionidae, which include several genera of unresolved taxonomic placement. The recent reassignment of the poorly studied Lamprotula rochechouartii from the Unionidae to the Margaritiferidae motivated a new search for other potential s ...

... Many methods in freshwater biomonitoring tend to be restricted to a few levels of biological organization, limiting the potential spectrum of measurable of cause-effect responses to different anthropogenic impacts. We combined distinct organisational levels, covering biological biomarkers (histopathological and biochemical reactions in liver and fish gills), community based bioindicators (fish gui ...

... Freshwater bivalves have been highly threatened by human activities, and recently their global decline has been causing conservational and social concern. In this paper, we review the most important research events in freshwater bivalve biology calling attention to the main scientific achievements. A great bias exists in the research effort, with much more information available for bivalve species ...

... The duck mussel, Anodonta anatina, has been described as abundant and widespread in Europe. However, it is listed as near threatened or threatened in several countries owing to severe declines in abundance and/or spatial distribution. Despite its potential ecological importance and conservation status almost nothing is known regarding its genetic diversity. As a preliminary analysis, variation wit ...

... A procedure to select the most relevant metrics for assessing the ecological condition of the Douro basin (north Portugal) was developed based upon a set of 184 benthic community metrics. They were grouped into 16 biological categories selected from literature using data collected over 2 years from 54 sites along 31 rivers covering the whole perceived range of human disturbance. Multivariate analy ...

... An important population of the critically endangered pearl mussel Margaritifera margaritifera (Linnaeus, 1758) was surveyed at the edge of its southern distribution (River Paiva, Portugal). Although an earlier study suggested that this population had a very low number of individuals (<500), a narrow distribution, and was mainly comprised by old specimens our data contradict these findings. Our ass ...